Okay, there is a difference in codec quality, though I think you are confused about what you are asking.
Codec are enCOder/DECoders that change a data stream into a sensory media (audio/video). there are different audio codecs (mp3, wma, wav, etc) and they can be encoded using different coders (mp3 has Lame, Fraunhofer, Xing, and Blade). So, if you are burning MP3s to a CD, to get the best quality (and yes, you can hear the difference) go for Lame encoding and decoding. It's the cheapest (free) and best sounding (really, it is) codec out there. In this case, however, it doesn't matter what sound card you have as you can burn CDs without even having a sound card.
Second, yes you can hear the difference between card manufacturers. They use different methods of converting that data stream into an audio clip. Some go cheap and get something that sounds "decent", while others spend time and money on R&D to get quality sound output. This is what M-Audio, RME, Audiotrak, and the like do, but Creative doesn't. Creative gives you those value-added features, while the others give you straight-out quality. M-Audio, Guillemot, and Audiotrak are my mainstream picks, while RME is my high-end pick. Creative can just pick my a$$.
XP 2500+ Barton
A7N8X Dlx
2x512MB Corsair PC3200
MSI GF3 Ti500 w/64MB DDR
16x DVD-ROM
2x80GB 7200RPM Maxtor
Onboard audio
My computer is bigger than your computer....